This invention relates to aircraft in general, and particularly to a vertical take-off and landing (VTOL) carrier capable of launching and retrieving any conventional fixed wing airplane, or transporting any type of other payload.
For purposes of this specification, "carrier" refers to a VTOL vehicle capable of launching and retrieving another aircraft; "aircraft" or "carried vehicle" refers to the airplane adapted to be launched and retrieved by the carrier; and "composite vehicle" refers to the combination of carrier and aircraft.
The concept of using a carrier vehicle to lift a second aircraft having greater horizontal range and speed is not new. An example of a design employing this concept is found in British Pat. No. 926,613, issued to Frederick, et al. In the Frederick, et al., design the carrier vehicle comprises an airfoil shaped body which serves both as a platform for the carried airplane and a housing for a plurality of jet engines.
One disadvantage to the Frederick, et al., platform is that the carried plane, when attached to the carrier, is directly above the carrier engines. This necessitates the provision of ductwork for the jet intakes which is both expensive and may interfere with the stability of the carried plane during separation or coupling.
A further drawback in the Frederick, et al., design is the necessity of ramps and a winch for rolling the carried plane on and off the platform while on the ground.
Several prior art designs take advantage of the lifting capability of helicopters. An example is found in U.S. Pat. No. 2,843,337, issued to Bennett. The major drawback of employing helicopter carriers is, again, that downwash from the rotary blades interferes with aircraft stability and the creation of lift prior to separation.
U.S. Pat. Nos. 3,000,593, issued to Eggers and Haberkorn; and 3,058,691, issued to Eggers, Dumey and Ernst disclose composite VTOL aircraft which attempt to overcome the problem of aerodynamic interference between the coupled vehicles by providing legs which vertically position the composite craft on the ground. Such an arrangement is undesirable in many applications because of the difficulty in landing an aircraft in a "tailsitting" position.
A further objection to most prior art schemes is the inadaptability of the carrier vehicle to an unlimited variety of fixed wing aircraft without extensive modification to the carried craft.